tamoxifen (redirected from 4-hydroxytamoxifen)

tamoxifen (təmŏk`sĭfĕn'), synthetic hormone used in the treatment of breast cancer. Introduced in 1978, tamoxifen is used to prevent recurrences of cancer in women who have already undergone surgery to remove their tumors. In 1998, a large study of healthy women at high risk for breast cancer showed that tamoxifen can also prevent first occurrence of the disease: women who took the drug had a 45% lower incidence of cancer that those who received a placebo. However, adverse effects (including uterine cancer) and other concerns await further study.

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tamoxifen

Synthetic hormone, marketed as Nolvadex, that prevents the binding of estrogen to estrogen-sensitive breast cancer cells. Initially used to prevent recurrences of breast cancer after successful treatment, it was later found to prevent first occurrences in women at high risk. The most serious side effect is an increased risk of thrombosis, which may require patients to take an anticoagulant as well. Studies on its effectiveness against breast and other cancers continue.